linux-kernel - Re: [PATCH v2 2/2] dmaengine: Add support for multiple descriptors for imx-dma.

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Thu, 1 Mar 2012 11:28:18 +0100
From:	javier Martin <javier.martin@...ta-silicon.com>
To:	Sascha Hauer <s.hauer@...gutronix.de>
Cc:	linux-arm-kernel@...ts.infradead.org, linux@....linux.org.uk,
	vinod.koul@...el.com, dan.j.williams@...el.com,
	linux-kernel@...r.kernel.org
Subject: Re: [PATCH v2 2/2] dmaengine: Add support for multiple descriptors
 for imx-dma.

Hi Sascha,

On 1 March 2012 11:19, Sascha Hauer <s.hauer@...gutronix.de> wrote:
> On Tue, Feb 28, 2012 at 05:08:18PM +0100, Javier Martin wrote:
>> dmaengine specifies the possibility that several descriptors
>> can be queued for transfer. It also indicates that tasklets
>> must be used for DMA callbacks.
>>
>> Signed-off-by: Javier Martin <javier.martin@...ta-silicon.com>
>
> Have you tested this patch with audio?

Yes,
I have a test battery which tests audio, mmc, runs dmatest module and
a custom mem2mem video device I'm developing.

>
>> +static int imxdma_xfer_desc(struct imxdma_desc *d)
>> +{
>> +     struct imxdma_channel *imxdmac = to_imxdma_chan(d->desc.chan);
>> +     int ret;
>> +
>> +     /* Configure and enable */
>> +     switch (d->type) {
>> +     case IMXDMA_DESC_MEMCPY:
>> +             ret = imx_dma_config_channel(imxdmac->imxdma_channel,
>> +                                       d->config_port, d->config_mem, 0, 0);
>> +             if (ret < 0)
>> +                     return ret;
>> +             ret = imx_dma_setup_single(imxdmac->imxdma_channel, d->src,
>> +                                        d->len, d->dest, d->dmamode);
>> +             if (ret < 0)
>> +                     return ret;
>> +             break;
>> +     case IMXDMA_DESC_CYCLIC:
>> +             ret = imx_dma_setup_progression_handler(imxdmac->imxdma_channel,
>> +                                                     imxdma_progression);
>> +             if (ret < 0)
>> +                     return ret;
>
> You fall through here. Is this intended? If yes, a comment would be good
> here.

Yes it is. cyclic is the same as slave_sg with the add-on of the
progression handler and a specific configuration of the sglist which
is done in 'imxdma_prep_dma_cyclic'.
Do you want me to send a new version with a comment on the matter?

-- 
Javier Martin
Vista Silicon S.L.
CDTUC - FASE C - Oficina S-345
Avda de los Castros s/n
39005- Santander. Cantabria. Spain
+34 942 25 32 60
www.vista-silicon.com
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/